[dmurray]

I would bet that it has already been soft-solved by kthejoker2 upthread who got it in 5 guesses. I can't conceive of 3 wrong words being enough to narrow it down to a single possibility.

Soft-solved in that he doesn't necessarily have a proof this is the optimal solution, nor an enumeration of all optimal solutions, nor the optimal play from any game state - so there's still plenty to be explored here

I wonder if the author can improve the adversarial methodology to prevent a solution in 5. Eg, being left with BLACK/FLACK/SLACK as options is worse than having TRACE/BRACE/TRACK/CRACK, because the former requires 3 guesses to solve and the latter can be done in two. (Maybe this example is impossible because of TRACT, but I'm certain this effect exists).

[Sesse__]

If you're left with BLACK/FLACK/SLACK, you guess BEEFS, which tells you which is the correct one. So two guesses, not three.